Advances of biological macromolecules hemostatic materials: A review.

Achieving hemostasis is a necessary intervention to rapidly and effectively control bleeding. Conventional hemostatic materials currently used in clinical practice may aggravate the damage at the bleeding site due to factors such as poor adhesion and poor adaptation. Compared to most traditional hemostatic materials, polymer-based hemostatic materials have better biocompatibility and offer several advantages. They provide a more effective method of stopping bleeding and avoiding additional damage to the body in case of excessive blood loss. Various hemostatic materials with greater functionality have been developed in recent years for different organs using diverse design strategies. This article reviews the latest advances in the development of polymeric hemostatic materials. We introduce the coagulation cascade reaction after bleeding and then discuss the hemostatic mechanisms and advantages and disadvantages of various polymer materials, including natural, synthetic, and composite polymer hemostatic materials. We further focus on the design strategies, properties, and characterization of hemostatic materials, along with their applications in different organs. Finally, challenges and prospects for the application of hemostatic polymeric materials are summarized and discussed. We believe that this review can provide a reference for related research on hemostatic materials, contributing to the further development of polymer hemostatic materials.

3D-bioprinted double-crosslinked angiogenic alginate/chondroitin sulfate patch for diabetic wound healing.

Improving chronic wound healing remains a challenge in the clinical practice. In this study, we developed double-crosslinked angiogenic 3D-bioprinted patches for diabetic wound healing by the photocovalent crosslinking of vascular endothelial growth factor (VEGF) using ultraviolet (UV) irradiation. 3D printing technology can precisely customize the structure and composition of patches to meet different clinical requirements. The biological polysaccharide alginate and chondroitin sulfate methacryloyl were used as biomaterials to construct the biological patch, which could be crosslinked using calcium ion crosslinking and photocrosslinking, thereby improving its mechanical properties. More importantly, acrylylated VEGF could be easily and rapidly photocrosslinked under UV irradiation, which simplified the step of chemically coupling growth factors and prolonged VEGF release time. These characteristics suggest that 3D-bioprinted double-crosslinked angiogenic patches are ideal candidates for diabetic wound healing and other tissue engineering applications.

RBFNN Design Based on Modified Nearest Neighbor Clustering Algorithm for Path Tracking Control.

Radial basis function neural networks are a widely used type of artificial neural network. The number and centers of basis functions directly affect the accuracy and speed of radial basis function neural networks. Many studies use supervised learning algorithms to obtain these parameters, but this leads to more parameters that need to be determined, thereby making the system more complex. This study proposes a modified nearest neighbor-based clustering algorithm for training radial basis function neural networks. The calculation of this clustering algorithm is not large, and it can adapt to varying densities. Furthermore, it does not require researchers to set parameters based on experience. Simulation proves that the clustering algorithm can effectively cluster samples and optimize the abnormal samples. The radial basis function neural network based on modified nearest neighbor-based clustering has higher accuracy in curve fitting than the conventional radial basis function neural network. Finally, the path tracking control based on a radial basis function neural network of a magnetic microrobot is investigated, and its effectiveness is verified through simulation. The test accuracy and training accuracy of the radial basis function neural network was improved by 23.5% and 7.5%, respectively.